Upon initiation of treatment, emergency medical technicians must often seek to administer intravenous fluids, especially to an individual who has sustained a trauma. This requires the initiation of a means of ingress to the patient's bloodstream, and is often hampered by injuries such as lacerations, scrapes, burns, etc. which limit the number of usable sites. Intravenous fluid administration devices often include a holder carrying a plastic catheter and a removable needle cannula passing through the distal tip of the catheter for inserting the needle and catheter through the skin and into a body vessel such as a vein. After successfully performing the venopuncture, the needle is removed and a source of infusion liquid such as glucose, blood, saline solution or other liquid is supplied to the holder to supply the infusion liquid to the vein.
As particular situations progress, critical response to divergent patient needs is of the utmost importance. Although it may be necessary to instill a variety of fluids and medications in varying amounts, the ability of the technician to accomplish this is often impaired by a paucity of viable infusion sites. For example, a patient's blood supply may be dangerously diminished, requiring rapid infusion of large volumes of replacement blood or plasma. This will require a relatively large bore catheter. Subsequently, conditions may arise requiring the continued supply of moderate amounts of intravenous fluid, while simultaneously requiring medications such as heart rhythm medications, seizure control medications, medications designed to control blood pressure fluctuations, etc. in order to maintain physiological stability. Instilling these medications often requires multiple means of ingress while maintaining separate and distinct flow paths so that intermixing of medications, and possible interactions thereof, are prevented.
It is known to form catheters with extremely large bores and to adapt these catheters for single or multiple lumens configurations. This enables the insertion of intravenous fluids, blood, drugs and/or the extraction of blood, via the same entry point, and without intermixing of the fluids. The problem which exists, is that these catheters are of such a large bore that they require surgical implantation by a physician in an emergency room or operating room. A sterile environment is required for their insertion, and a local anesthetic is generally administered to facilitate the procedure.
U.S. Pat. No. 5,149,330 to Brightbill describes such a catheter which is capable of being converted from a single lumen catheter into a multilumen catheter. The Brightbill device is designed for use during a surgical procedure where a large bore catheter is initially required to be surgically inserted so as to provide a means of ingress for large quantities of blood or other fluids. After completion of the surgery, Brightbill supplies a multilumen insert which is mateable with the large bore catheter and is capable of converting this large bore catheter to function as a multilumen catheter without the necessity of removal of the large bore device. The first elongated large-bore device of Brightbill is described as being 13 gauge or larger, e.g. having an outer diameter of at least 0.092 inches. The second catheter is described as having an internal diameter on the order of 0.047" or 16 gauge while the internal lumens are 18 gauge. Such devices have great utility in an operating room environment but are not suitable for emergency use by a nurse or emergency medical technician.
Unfortunately, the presently available catheters which are suitable for field usage do not allow for convertibility from large to small size or from single to multilumen configurations.
Thus, what is lacking in the art is a convertible catheter which is of a size and construction so as to enable it to be inserted by a medical technician and is designed so as to convert the site of ingress from a single lumen configuration to a multilumen configuration without necessitating removal of the first catheter.